. >> gearing up, president obama and mitt romney prepare for their first debate. a show down in denver this wednesday. >>> and on the record, arnold schwarzenegger opens up on "60 minutes" about the affair that produced a son and ended his marriage. >> it was the stupidest thing i've done in the whole relationship. >> this is the "cbs morning news" for monday, october 1, 2012. >>> good morning. good to be with you. i'm terrell brown. this morning in afghanistan the taliban is claiming responsibility for a suicide attack that killed at least 14 people, including three nato service members. a suicide bomber riding a motorcycle rammed into a patrol. americans have a large presence there. nato is trying to sort out a weekend attack in afghanistan that left two americans dead. the casualties push the number of u.s. personnel killed in afghanistan to 2,000. the circumstances of saturday's violence remains unclear but a fire fight broke out at a checkpoint in eastern afghanistan. what nato hasn't determined so far was the gun battle a result of an insider attack or a deadly misunderstanding.